1950 AJS Model 18: Carburettor Problem

blythmags · Post by **blythmags** » Sat May 05, 2012 8:14 pm

Hi all

I have recently drained the carb of a little water when my bike was delivered to me recently in the pouring rain, following timing adjustment. The guy who did the timing advised me to drain any water that may have got into the carb if it didnt start, which I duly did....and yes.....I failed to kick the bike over. He duly returned to find that the float was either sticking or the needle was out of cinque ( not sure which !)....he loosened same and it kicked over ok.

On my first look at the bike today, I turned the petrol tap on and in a few seconds the petrol started streaming from the carburettor inlet vents ( I think thats what they are called ?). all over the bike.

Any ideas what could be the the problem ?

Merlin · Post by **Merlin** » Sat May 05, 2012 8:36 pm

Sounds like either the float needle has not seated properly or the float is not floating either way petrol is passing where it should not.

56G80S · Post by **56G80S** » Sun May 06, 2012 12:35 am

Not a problem I've had, but if it has a "tickler" could that be stuck?

Johnny B

wilko · Post by **wilko** » Sun May 06, 2012 12:54 am

Lap the needle into it's seat with regular colgate toothpaste. (Yes i own the company)!

blythmags · Post by **blythmags** » Sun May 06, 2012 6:56 am

Hi everyone

Thanks for the advice. The tickler apears to work fine and the float has no apparent damage to it.

Can I ask whether there are any straight forward ways and I guess more importantly for me, instructions how to ensure the needle is seated properly, reminding everyone that I am an absolute mechanical novice ?.....

Thank you

paul knapp · Post by **paul knapp** » Sun May 06, 2012 8:19 am

Make sure the float clip is in the float needle groove and hasn't slipped up a bit.

While you have the bowl top off doing this check, turn the fuel on and watch the float rise.
When it stops rising but the fuel level continues to rise, something is stopping the needle from seating in its seat in the bowl bottom.

As said above, lap the needle in the seat.
Our Colgate is made in Thailand , so I use Oz Brasso!

Don't worry about being a 'mechanical novice', every poster here was the same once.
(...and some still are!)

blythmags · Post by **blythmags** » Sun May 06, 2012 8:56 am

Hi Paul

Thanks for the reply. Could you explain in pure novice terms how to "lap the needle in the seat" ?. I'm going to have a go at this today !

paul knapp · Post by **paul knapp** » Sun May 06, 2012 2:17 pm

With out going into detail here, have a look at previous posts on the subject.
...in the forum search box, type in; "float needle lapping"

Though, if the bowl is flooding as quick as you say, the problem is more likely to be a sticking needle, not a leaky seat.